That's because Roman philosopher Seneca, who died in A.D. 65, had predicted the Earth would go up in smoke: "All we see and admire today will burn in the universal fire that ushers in a new, just, happy world," he said, according to the 1999 book Apocalypses.

The end never came, but that hasn't stopped people—over centuries and across cultures—from forecasting our collective doom. Click through the gallery for a sampling of end-of-the-Earth scenarios.

November 4, 2009

Great Fire of London

Artwork from Getty Images/Bridgeman Art Library

Many Christian Europeans entered the year 1666 with trepidation: The Bible describes 666 as the ominous Number of the Beast.

A prolonged plague that had wiped out much of London's populace in 1665 didn't help assuage fears, and when the Great Fire of London (pictured in an illustration) occurred, many believed their time had come.

For instance, Londoners saw the fire as "dreadful judgment—God's wrath visited at last on a sinful Earth," according to the 2002 book The Great Fire of London: In That Apocalyptic Year, 1666.

November 4, 2009

Halley's Comet

The appearance of Halley's comet—which is seen from Earth every 76 years—has been seen as an omen of disaster throughout history.

The comet's impending arrival in 1910, for instance, stirred apocalyptic hysteria among Europeans and Americans (pictured, a French cartoon ridiculing the doomsayers), many of whom believed that the comet's tail contained a gas "that would impregnate the atmosphere and possibly snuff out all life on the planet," according to French astronomer Camille Flammarion, as quoted in the book Apocalypses.

Some profited from the panic: Sales of masks and "comet pills" skyrocketed, as did oxygen supplies, especially in Rome, where people hoped to keep themselves alive on bottled air until Earth passed through the comet's tail, the book said.

November 4, 2009

Planetary Alignments

Photograph by Your Shot user Benjamin Cooper

The moon and Venus join together in a conjunction over the Ponce Inlet Lighthouse in Florida on February 27, 2009.

Such planetary alignments have inspired many doomsday forecasts, particularly around the May 5, 2000, conjunction, when Mercury, Venus, Mars, Jupiter, and Saturn lined up with the sun and the moon, according to New Scientist.

Author Richard Noone predicted ice would overtake the world (see eighth photo), and "psychic archaeologist" Jeffrey Goodman asserted in his 1977 book We Are the Earthquake Generation that "quakes and volcanoes [will be] set off around the world and a rift [will] open up as the Earth splits in several places to relieve the stress produced by the shift," New Scientist reported.

But doom and gloom can also spark scientific innovation, as occurred in 1774 in Friesland, the Netherlands. A vicar hoping to boost his congregation circulated a "little book of doom" that said the solar system would be demolished during an upcoming conjunction, according to New Scientist.

As townspeople's panic grew, an amateur astronomer built a planetarium in his living room to allay concerns and explain the true movements of the planets—now the oldest working mechanical planetarium in the world.

November 4, 2009

Jehovah's Witnesses

Photograph from Hulton Archive/Getty Images

Since its founding in the 1870s, the Jehovah's Witnesses, a Christian offshoot, had prophesied that the world would end in 1914 (above, a Jehovah's Witness family hangs posters in the 1930s).

Though nothing of the sort happened in 1914, ever since then, the religion's followers have been predicting that the world will end "shortly," according to the 1997 book Apocalypse Delayed: The Story of Jehovah's Witnesses.

November 4, 2009

Pat Robertson

Photograph by Gene J. Puskar, AP

Television evangelist Pat Robertson (pictured in a 2000 photograph) preached that sometime in the 1980s, Jesus would return to Earth.

The event—called the Rapture—was forecast based on writings in the Bible, specifically I Thessalonians, which states: "For the Lord Himself shall descend from heaven with a shout, with the voice of the archangel, and with the trumpet of God. And the dead in Christ shall rise first; then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air," according to The Atlantic.

Under that scenario, unbelievers and Satan will be trapped in a lake of fire, where they will be tormented day and night forever, the Atlantic said. Fire will also destroy Earth and replace it with a new heaven and Earth, where believers—or the redeemed—will live.

November 4, 2009

Comet Hale-Bopp

Photograph by Alastair Grant, AP

The extremely bright comet Hale-Bopp, discovered in 1995, last buzzed Earth in March 1997 (above, the tail seen over Stonehenge on March 28)—but its appearance was met with tragedy.

Thirty-nine people, part of a religious group called Heaven's Gate, committed suicide in California when the comet was at its closest. The group believed that a UFO riding the comet's wake would rescue them from a doomed Earth.

The followers thought that Lucifer controlled the Earth and that humans "were about to perish in apocalyptic flames," according to the book Apocalypses.

November 4, 2009

Richard Noone

Photograph by Paul Nicklen, National Geographic Stock

In his 1997 book Ice: The Ultimate Disaster, author Richard Noone predicted that on May 5, 2000, the planets would perfectly align—and end life as we know it by sending melting ice (above, the Austfonna ice cap melts during the Arctic summer) barreling toward Earth's Equator.

Noone argued in the book that Earth's previous axis shifts had coincided with tremendous climatic changes—such as ice ages—and that such "almost unimaginable results" would happen again.

Year 2000

The Head family displays survival supplies meant to carry the family through the supposed millennium apocalypse caused by the Y2K computer bug in an undated photograph.

A 1984 computer-trade publication first warned of a cataclysm occurring on January 1, 2000, the Wall Street Journal reported, when a bug caused by a calculation error would cripple computers and other machines and lead to mass chaos. The column described how to purchase an anti-Y2K amulet and lifesaving Y2K-repair tools, the paper said.

Evangelicals also recommended that their followers stockpile food and prepare for the worst, according to the Washington Post. Such leaders as Jerry Falwell and Pat Robertson (see sixth photo) hinted that the turn of the millennium would bring Christ's return, as described in the Book of Revelation, the Post reported.

November 4, 2009

Large Hadron Collider

Photograph by Salvatore Di Nolfi, Keystone/AP

When the Large Hadron Collider fired up in September 2009, some critics speculated that the world's biggest atom smasher could spawn a black hole that would devour Earth.